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I have been having an interference problem with a short (1.5m) run of HDMI cable between my laptop and screen for quite some time.

My setup is as follows:

I live in a university residence and my laptop (Dell XPS 16), screen (Dell 24" 1080x1920) and fridge are in close proximity to one another.

The problem presents itself as follows:

For reference it is remarkably similar to this issue discussed in this post but I have learned some more through experimentation.

The dropouts occur when me or my roommate’s fridge’s thermostat kicks in or out thus leading me to believe there is some problem with the cable. Also, when placing my mobile phone (Blackberry Curve 8250) on the HDMI cable and initiating a data connection it also drops out.

The Cable:

$5 Ebay cable that works fine otherwise. I suspect the plastic molds near the ends are fake and do not contain real ferrites.

Here is a picture:

enter image description here


  • Is there some way to better shield the cable or otherwise resolve the problem?
  • Should I cut open the molds to see if there are ferrites inside?
  • Should I buy a new one?
    • And if so, what should I look for in a new cable to prevent this?
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From your question I wouldn't be convinced that the cable is at fault. I suppose there could be endless reasons. But it should be easy to confirm. I'm pretty sure you can borrow a hdmi cable for an afternoon to test. – bdecaf May 25 '12 at 11:25
I am going to run around and try to find another HDMI cable... Will update. – Konsalik May 25 '12 at 12:01

Yes there are lots of other cables with different shielding. If the shielding is good they are advertised by something like fully shielded or 3-layer shielding or something like this. I seems that the one you have does not have much. Other than cable shielding, the covering of connectors is also important. Yours have a plastic covering, better versions have ceramic shielding for the connectors.

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up vote 0 down vote accepted

After playing around with proper cables and removing the insulation off the Ebay ones, I came to the realisation that the cheap cables had no foil or wire shielding. This also resulted in the case of the connector not being grounded.

Replacement with another cable with sufficient shielding and proper grounding resolved all issues.

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I know this sounds very conspiracy-nutty, but you can create a very cheap and somewhat effective shield using tin foil (aluminum foil) to wrap the cable end to end and then making sure the foil wrap is unbroken and earthed (I've done this with the top pin of a UK plug and occasionally other places). It has the advantage of being very cheap to try, so no reason not to give it a shot - certainly before you go sourcing other cables.

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I thought of this but wasn't sure it would work, will definitely try and update. – Konsalik May 25 '12 at 12:01
This is a ridiculous unpractical fix, the foil would break with any flex of the cable or where it rubbed on a surface, especially a 1.5M long one. Plus, why use up $2 of tin foil for a bad fix for a $5 cable? Serious false economy. – Amicable May 25 '12 at 12:30
Personally I have enough lying around at home to just do it, and hey, you don't have to do it at all - it's just a suggestion, people get very upset about the most minor of things – Adam C May 25 '12 at 13:05
I'm not upset or offended by your answer, this is a help website and you posted what I consider to be a poor answer. You shouldn't take it personally either. – Amicable Jun 18 '12 at 15:17
adding the word ridiculous makes it something more than a general criticism though. I don't take things like that personally, believe me, I have done support for a living. As a general tip - more answers and less snarky criticism might get you more rep – Adam C Jun 18 '12 at 18:00

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